From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 26 Aug 2011 11:52:37 +0000 (+0300)
Subject: Better PNG error reporting
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=1f842b63c6e1751b2017f5c4b67d50e2fc911e55;p=libs%2Fgui.git

Better PNG error reporting
---

diff --git a/source/graphics/image_png.cpp b/source/graphics/image_png.cpp
index 256159c..f224786 100644
--- a/source/graphics/image_png.cpp
+++ b/source/graphics/image_png.cpp
@@ -3,14 +3,28 @@
 #include "image_png.h"
 #include "image_private.h"
 
+using namespace std;
+
 namespace {
 
+struct ErrorInfo
+{
+	string msg;
+};
+
 void read(png_struct *png, png_byte *data, png_size_t size)
 {
 	Msp::IO::Base *in = reinterpret_cast<Msp::IO::Base *>(png_get_io_ptr(png));
 	in->read(reinterpret_cast<char *>(data), size);
 }
 
+void error(png_struct *png, const char *msg)
+{
+	ErrorInfo *error_info = reinterpret_cast<ErrorInfo *>(png_get_error_ptr(png));
+	error_info->msg = msg;
+	longjmp(png_jmpbuf(png), 1);
+}
+
 }
 
 
@@ -30,11 +44,12 @@ void load_png(IO::Base &in, Image::Private &priv)
 
 	try
 	{
-		png = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
+		ErrorInfo error_info;
+		png = png_create_read_struct(PNG_LIBPNG_VER_STRING, &error_info, error, 0);
 		info = png_create_info_struct(png);
 
 		if(setjmp(png_jmpbuf(png)))
-			throw bad_image_data("PNG error");
+			throw bad_image_data(error_info.msg);
 
 		png_set_read_fn(png, &in, read);
 		png_read_info(png, info);